At&t Note 4 Connection Issues

I have At&t Note 4 Unlocked and use it on T-mobile. So, I just updated my At&t Note 4 to 5.0.1 Lollipop using my cousins at&t sim. After the update I was so happy but then by the end of the day I started noticing an issue. So, I turn off data and WiFi when I want to conserve battery and don't want to use my phone. After the update I started to notice that I was still receiving notifications and was able to surf the web, go on Instagram and Snapchat basically all the things that needs some kind of connection to work, was still working. Even though my WiFi and data connection was off. So I went in and looked at what was being used my WiFi or data, it ended up being my data but it was never on and the little 4GLTE sign in the notification bar was not there but it was still being used and I am sure because the MB usage kept going up. But its off so what is going on I am so confused because I can usually find out the problem. I even called Samsung for this and their methods didn't work. Please someone help me.

If it's off and you have not factory reset since the upgrade, it might be a good idea to turn it on and then back off again to make sure there isn't some oddity in the upgrade that caused it to be set on silently.